From f262d114ddfe11bad7b2f109cb965873f132f74e Mon Sep 17 00:00:00 2001
From: Max Reitz <mreitz@redhat.com>
Date: Sat, 13 Jun 2015 16:22:02 +0200
Subject: [PATCH 08/42] qcow2: Add qcow2_signal_corruption()
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Message-id: <1434212556-3927-9-git-send-email-mreitz@redhat.com>
Patchwork-id: 66027
O-Subject: [RHEL-7.2 qemu-kvm PATCH 08/42] qcow2: Add qcow2_signal_corruption()
Bugzilla: 1129893
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

BZ: 1129893

Add a helper function for easily marking an image corrupt (on fatal
corruptions) while outputting an informative message to stderr and via
QAPI.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Message-id: 1409926039-29044-3-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 85186ebdac7e183242deaa55d5049988de832be1)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

Conflicts:
	block/qcow2.c

No qapi_event_send_*() downstream.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 block/qcow2.h |  5 +++++
 2 files changed, 67 insertions(+)

diff --git a/block/qcow2.c b/block/qcow2.c
index 6026f8a..be7e8e8 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -31,6 +31,8 @@
 #include "qapi/qmp/qerror.h"
 #include "qapi/qmp/qbool.h"
 #include "qapi/util.h"
+#include "qapi/qmp/types.h"
+#include "monitor/monitor.h"
 #include "trace.h"
 
 /*
@@ -2329,6 +2331,66 @@ static int qcow2_amend_options(BlockDriverState *bs,
     return 0;
 }
 
+/*
+ * If offset or size are negative, respectively, they will not be included in
+ * the BLOCK_IMAGE_CORRUPTED event emitted.
+ * fatal will be ignored for read-only BDS; corruptions found there will always
+ * be considered non-fatal.
+ */
+void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
+                             int64_t size, const char *message_format, ...)
+{
+    BDRVQcowState *s = bs->opaque;
+    char *message;
+    QObject *data;
+    va_list ap;
+
+    fatal = fatal && !bs->read_only;
+
+    if (s->signaled_corruption &&
+        (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT)))
+    {
+        return;
+    }
+
+    va_start(ap, message_format);
+    message = g_strdup_vprintf(message_format, ap);
+    va_end(ap);
+
+    if (fatal) {
+        fprintf(stderr, "qcow2: Marking image as corrupt: %s; further "
+                "corruption events will be suppressed\n", message);
+    } else {
+        fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal "
+                "corruption events will be suppressed\n", message);
+    }
+
+    assert((offset >= 0) == (size >= 0));
+
+    if (offset >= 0) {
+        data = qobject_from_jsonf("{ 'device': %s, 'msg': %s, 'offset': %"
+                                  PRId64 ", 'size': %" PRId64 ", 'fatal': %s }",
+                                  bdrv_get_device_name(bs), message,
+                                  offset, size, fatal ? "true" : "false");
+    } else {
+        data = qobject_from_jsonf("{ 'device': %s, 'msg': %s, 'fatal': %s }",
+                                  bdrv_get_device_name(bs), message,
+                                  fatal ? "true" : "false");
+    }
+
+    monitor_protocol_event(QEVENT_BLOCK_IMAGE_CORRUPTED, data);
+    qobject_decref(data);
+
+    g_free(message);
+
+    if (fatal) {
+        qcow2_mark_corrupt(bs);
+        bs->drv = NULL; /* make BDS unusable */
+    }
+
+    s->signaled_corruption = true;
+}
+
 static QEMUOptionParameter qcow2_create_options[] = {
     {
         .name = BLOCK_OPT_SIZE,
diff --git a/block/qcow2.h b/block/qcow2.h
index e958ab4..2138462 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -252,6 +252,7 @@ typedef struct BDRVQcowState {
     bool discard_passthrough[QCOW2_DISCARD_MAX];
 
     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
+    bool signaled_corruption;
 
     uint64_t incompatible_features;
     uint64_t compatible_features;
@@ -468,6 +469,10 @@ int qcow2_mark_corrupt(BlockDriverState *bs);
 int qcow2_mark_consistent(BlockDriverState *bs);
 int qcow2_update_header(BlockDriverState *bs);
 
+void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
+                             int64_t size, const char *message_format, ...)
+                             GCC_FMT_ATTR(5, 6);
+
 /* qcow2-refcount.c functions */
 int qcow2_refcount_init(BlockDriverState *bs);
 void qcow2_refcount_close(BlockDriverState *bs);
-- 
1.8.3.1